1. Field of the Invention
The present invention relates to a device for determining speed when sporting goods implements, particularly, such as a golf club, a baseball bat, etc is swung.
2. Description of the Prior Art
Devices used to measure swing speed or the like of a golf club or a baseball bat heretofore proposed include, for example, a needle-movable type in which a spring is extended by a centrifugal force produced at the time of swing to move a needle, and after swinging has been finished, the spring is returned to its original position with the result that the needle remains stopped at a position in which it has moved to determine the maximum centrifugal force (head speed) (see Japanese Utility Model Application Laid-open Nos. 60-7,858 and 60-32,972); a system in which the sound through the air is produced by air resistance caused by swinging (see Japanese Utility Model Application No. 60-30,267); a system in which a propeller is provided, and a measured value is calculated from rotation of the propeller (see Japanese Patent Publication No. 51-10,536); and a system in which a centrifugal force produced when swinging is made is applied to a weight being normally tensioned by means of a spring to rotate the weight which then comes into contact with a stopper thereby determining whether or not a set swing speed comes out (see Japanese Utility Model Publication No. 49-12,125).
However, the above-described conventional devices have been proposed to measure a swing speed to calculate a distance covered or flow, or to merely determine whether or not a set swing speed was reached, but were not possible to find whether or not the maximum speed (maximum accleration) as reached at a reasonable position in a swinging orbit, and what that speed it was. That is, there has been encountered problems that swinging in the proper form suitable for respective players cannot be determined; and in addition, a player is apt to swing with all his strength and when measurement is made, his swing form tends to get out of shape.